Memory-Level Parallelism (MLP) is the ability to perform multiple memory transactions at once. In many architectures, this manifests itself as the ability to perform both a read and write operation at once, although it also commonly exists as being able to perform multiple reads at once. It is rare to perform multiple write operations at once, because of the risk of potential conflicts (trying to write two different values to the same location).

Notice that this is not the same as vectorized memory operations, such as reading 4 separate but contiguous 8-bit values in a single 32-bit read.